DESCRIPTION (adapted from the application): The long range goal of the proposed research is to analyze cytokine regulation of endocytosis and antigen presentation in macrophages in order to maximize the immune response to HIV-1 antigens. This project will test the hypothesis that IL-13 enhances CD4+ T cell responses when used as an adjuvant for HIV-1 gp120 antigens in vivo by increasing macrophage antigen processing within early endosomes, and thereby increasing antigen presentation. To do this, the investigators will immunize mice with bovine RNAase or gp120 SF2 in the presence or absence of IL-13, and test the T cell responses against both RNAase, which has known early and late endosome-derived epitopes, and in parallel, against gp120 epitopes.